Mumin Sahin

An experimental study on friction welding of medium carbon and austenitic stainless steel components

In the presented study, AISI 1040 medium carbon steel and AISI 304 austenitic stainless steel parts were joined by friction welding. The welding process was carried out under optimized conditions using statistical approach. Tension tests were applied to welded parts to obtain the strength of the joints. Fatigue properties were additionally obtained experimentally under fluctuated tensile loads. Finally, notch impact tests were applied to the joints. Microstructures using microphotographs were examined in the heat affected zone of welded parts. Hardness variations in welding zone were also obtained. Experimental results were compared with those of previous studies.

An investigation on the effect of dimensional differences in friction welding of AISI 1040 specimens

Most of the machine parts can be produced using several manufacturing methods, such as forging, machining, casting or welding. The type of manufacturing method may be selected with respect to production costs of the alternatives for individual parts. In the presented study, an experimental friction welding set‐up was designed and constructed in order to investigate the effects of some welding parameters on the welding quality. The set‐up was constructed as continuous‐drive. Several groups of specimen were machined from the same material. Some pilot welding experiments under different process parameters were carried out in order to obtain optimum parameters according to statistical approach. The strengths of the joints were determined by tension tests, and the results were compared with those of specimens material. Addition to the tensile test data, hardness variations and microstructures in the welding‐ zone were obtained and examined.

An investigation into joining of austenitic‐stainless steels (AISI 304) with friction welding

Purpose – Aims to determine if friction welding is suitable for welding austenitic stainless steel (AISI 304)Design/methodology/approach – Uses an experimental continuous drive friction welding set‐up. Determined the strength, hardness and microstructure of the joined parts.Findings – Finds that the joint strengths are 96 per cent of those of the base metals with no significant hardening.Practical implications – Friction welding is an appropriate joining method for austenitic stainless steel (AISI 304).Originality/value – Aids in understanding appropriate uses of friction welding for joining stainless steel.

Joining of stainless steel and copper materials with friction welding

Purpose – The purpose of this paper is to investigate mechanical and metallurgical variations at interfaces of commercial austenitic‐stainless steel and copper materials welded by friction welding.Design/methodology/approach – In this paper, austenitic‐stainless commercial steel and copper materials are welded using the friction welding method. The optimum parameters are obtained for the joints. The joints are applied to the tensile and micro‐hardness tests. Then, micro‐ and macro‐photos of the joints are examined.Findings – It is found that some of the welds show poor strength depending on some accumulation of alloying elements at the interface result of temperature rise and the existence of intermetallic layers.Research limitations/implications – It would be interesting to search about the toughness values and fatigue behaviour of the joints. It could be a good idea for future work to concentrate on the friction welding of these materials.Practical implications – Friction welding can be achieved at high...

Effect of surface roughness on weldability in aluminium sheets joined by cold pressure welding

Purpose – The purpose of this paper is to examine the effects of the welding deformation and surface roughness in cold pressure welding on the tensile strength and the fatigue strength of joined sheets. Additionally, the paper seeks to analyse the hardness variations and microstructures at the welding interface.Design/methodology/approach – Cold pressure welding is a method of joining similar or dissimilar ductile metals. It can be applied by bringing into close contact the surfaces of virgin metal specimens that appear due to the breakdown of the surface layers caused by bulk plastic deformation. Cold pressure welding is applied to test parts without too long a delay after the preparation of surfaces. The application of welding in 10 min affects importantly the weld strength. As this time is increased, the weld strength of the joints is decreased. The determination of deformation amount is found by determination of the reduction (R) at the total thickness of the two parts after the welding process.Findin...

Characterization of Properties in Friction Welded Stainless Steel and Copper Materials

The aim of this study is to investigate the metallurgical and mechanical properties of friction welded stainless steel-copper joints. One of the manufacturing methods used to produce parts made from different materials is the friction welding method. Application of classical welding techniques to such materials is difficult because of they have different thermal properties. Stainless steel-copper joints are inevitable for certain applications due to unique performances such as higher electric conductivity, heat conductivity, corrosion resistance, and mechanical properties. In the present study, austenitic stainless steel and copper parts were joined by friction welding. Tensile, fatigue, and notch-impact tests were applied to friction welded specimens, and the results were compared with those for the original materials. Microstructure, energy dispersive x-ray, and x-ray diffraction (XRD) analysis and hardness variations were conducted on the joints. Results showed that various intermetallic phases such as FeCu4 and Cu2NiZn occurred at the interface. It was found from the microstructure and XRD analysis that intermetallic phases formed in the interface which further caused a decrease in the strength of the joints. However, hardness of the copper increased slightly, whereas the hardness of steel decreases slightly on the horizontal distance from the center.

Evaluation of temperature and properties at interface of AISI 1040 steels joined by friction welding

Purpose – The purpose of this paper is to evaluate temperature and properties at interface of AISI 1040 steels joined by friction welding.Design/methodology/approach – In this study, AISI 1040 medium carbon steel was used in the experiments. Firstly, optimum parameters of the friction welding were obtained by using a statistical analysis. Later, the microstructures of the heat‐affected zone are presented along with micro hardness profiles for the joints. Then, the temperature distributions are experimentally obtained in the interface of the joints that is formed during the friction welding of 1040 steels with the same geometry. This study was carried out by using thermocouples at different locations of the joint‐interface. The results obtained were compared with previous studies and some comments were made about them.Findings – It was discovered that temperature had a substantial effect on the mechanical and metallurgical properties of the material.Research limitations/implications – The maximum temperatu...

Characterization of properties in friction-welded austenitic-stainless steel and aluminium joints

Purpose – The main purpose of the present study was to evaluate the metallurgical and mechanical properties of dissimilar metal friction welds (FWs) between aluminium and type 304 stainless steel. Design/methodology/approach – One of the manufacturing methods used to produce parts made from different materials is the FW method. Therefore, in the present study, austenitic stainless steel and aluminium parts were joined by FW. Tensile, fatigue and notch-impact tests were applied to FW specimens, and the results were compared with those for the original materials. Microstructure, energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis and hardness variations were conducted on the joints. Findings – It was found from the microstructure and XRD analysis that inter-metallic phases formed in the interface which further caused a decrease in the strength of the joints. Research limitations/implications – In this study, the rotation speed was kept constant. The effects of the rotation speed on the weldin...

Materials flow for different lubricants during cold forming

Purpose – Barreling contour variations on the free surfaces of cylindrical upset specimen are to handle measuring for different upsetting reductions and different lubrication conditions in this study. The purpose of this paper is to address this issue.Design/methodology/approach – The materials flow for various materials using different lubricants in upsetting was investigated in this study. SAE 1020 steel, commercially pure copper and CuZn40Pb2 brass were used as the test materials. Upsetting process was applied to the cylindrical specimens using flat end dies. Three types of lubricants, namely grease, graphite and SAE 40 oil, were used in this study. Experiments were performed using a hydraulic press, which has 5 mm/s ram speed, and with a capacity of 150 metric tons.Findings – Variations of barrel radius change clearly with increasing deformation ratio depending on lubricant type. Radius values are different to each other for SAE 1020, Cu and brass specimens. It was understood that surface roughness ef...

An investigation into reutilizing of waste materials using friction welding and upset manufacturing methods

Purpose – The present study seeks to examine the possibilities of combined usage of friction welding and plastic forming in recycling of bar‐shaped waste materials.Design/methodology/approach – If the waste materials can be reproduced using various manufacturing methods without melting, their economic values could be increased economically. For this reason, using a combination of friction welding and plastic forming was chosen as an alternative recycling method. Upsetting was chosen as the plastic forming method due to its ease of application.Findings – In the present study, dimensional changes, hardness variations in heat affected zone (HAZ), variations of torsion and tensile strengths with upsetting ratio of specimens were examined. Hardness values of test material are raised to higher levels within the HAZ by the local hardening. The maximum shear stress in torsion and the tensile strengths of specimens are closely harmonious with hardness values of test material.Research limitations/implications – Alt...